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United States Patent | 5,748,156 |
Weber | May 5, 1998 |
An antenna structure has a rotatable dipole array constituting a driven antenna element, a cup mounted around the dipole, a first conductor connected to and extending from the antenna, and a first dielectric mounted around the first conductor. A second conductor is mounted around the first dielectric, and a second dielectric is mounted around the second conductor. A third conductor is mounted around the second dielectric, and the first and second conductors form a quarter-wavelength transformer. The first dielectric maintains a uniform spacing between the first and second conductors, and the third conductor defines a radio-frequency coupling cavity. The second dielectric electrically enlarges the cavity. Thus the physical dimensions of the structure can be reduced without sacrifice of its electrical properties.
Inventors: | Weber; John G. (Boulder Creek, CA) |
Assignee: | Chaparral Communications (San Jose, CA) |
Appl. No.: | 649928 |
Filed: | May 16, 1996 |
Current U.S. Class: | 343/762; 343/763; 343/791; 343/792; 343/821 |
Intern'l Class: | H01Q 003/00 |
Field of Search: | 343/761,763,766,786,789,790,791,820,821,822,863,864,792,762 |
2407057 | Sep., 1946 | Carter | 343/821. |
2412867 | Dec., 1946 | Briggs et al. | 343/761. |
2478313 | Sep., 1949 | Peterson | 343/821. |
2491493 | Dec., 1949 | Goldberg | 343/761. |
2509283 | May., 1950 | Wolf | 343/792. |
2542844 | Feb., 1951 | Smith | 343/864. |
2552146 | May., 1951 | Brown | 343/821. |
3230534 | Jan., 1966 | Luke et al. | 343/821. |
4109254 | Aug., 1978 | Wolosczuk | 343/840. |
4504836 | Mar., 1985 | Seavey | 343/797. |
4841261 | Jun., 1989 | Augustin | 343/763. |
4940989 | Jul., 1990 | Austin | 343/792. |
5103237 | Apr., 1992 | Weber | 343/786. |
5248988 | Sep., 1993 | Makino | 343/790. |
5392055 | Feb., 1995 | Madnick et al. | 343/790. |